Include some Land Cress in your herbal mix. This herb is particularly effective against Cabbage Moth caterpillars but does also work to some reasonable degree for other species. When the caterpillars eat the Cress they are killed, the benefit is increased as Cabbage moths are so attracted they will lay their eggs on the Cress even if other types of plants they like are in that area. Other caterpillar producing layers will also attempt to lay their eggs on the Cress.
Cress also makes a very nice addition to your herbs for human consumption.